Photopatterning of skin

ABSTRACT

Methods and systems for treating skin for aesthetic or health purposes are described. According to various embodiments, photoresponsive materials and light are delivered in a controlled fashion to produce a patterned distribution of a material in the skin.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to, claims the earliest availableeffective filing date(s) from (e.g., claims earliest available prioritydates for other than provisional patent applications; claims benefitsunder 35 USC § 119(e) for provisional patent applications), andincorporates by reference in its entirety all subject matter of thefollowing listed application(s) (the “Related Applications”) to theextent such subject matter is not inconsistent herewith; the presentapplication also claims the earliest available effective filing date(s)from, and also incorporates by reference in its entirety all subjectmatter of any and all parent, grandparent, great-grandparent, etc.applications of the Related Application(s) to the extent such subjectmatter is not inconsistent herewith. The United States Patent Office(USPTO) has published a notice to the effect that the USPTO's computerprograms require that patent applicants reference both a serial numberand indicate whether an application is a continuation or continuation inpart. The present applicant entity has provided below a specificreference to the application(s) from which priority is being claimed asrecited by statute. Applicant entity understands that the statute isunambiguous in its specific reference language and does not requireeither a serial number or any characterization such as “continuation” or“continuation-in-part.” Notwithstanding the foregoing, applicant entityunderstands that the USPTO's computer programs have certain data entryrequirements, and hence applicant entity is designating the presentapplication as a continuation in part of its parent applications, butexpressly points out that such designations are not to be construed inany way as any type of commentary and/or admission as to whether or notthe present application contains any new matter in addition to thematter of its parent application(s).

RELATED APPLICATIONS

1. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation in part of currently co-pendingUnited States patent application entitled METHOD AND SYSTEM FORTEMPORARY HAIR REMOVAL, naming Bran Ferren, Muriel Y. Ishikawa, EdwardK. Y. Jung, Nathan P. Myhrvold, Clarence T. Tegreene, and Lowell L.Wood, Jr. as inventors, U.S. application Ser. No. 11/073,361, filed Mar.4, 2005.

2. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation in part of currently co-pendingUnited States patent application entitled HAIR TREATMENT SYSTEM, namingBran Ferren, Muriel Y. Ishikawa, Edward K. Y. Jung, Nathan P. Myhrvold,Clarence T. Tegreene, and Lowell L. Wood, Jr. as inventors, U.S.application Ser. No. 11/072,698, filed Mar. 4, 2005.

3. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation in part of currently co-pendingUnited States patent application entitled HAIR REMOVAL SYSTEM WITH LIGHTSOURCE ARRAY, naming Bran Ferren, Muriel Y. Ishikawa, Edward K. Y. Jung,Nathan P. Myhrvold, Clarence T. Tegreene, and Lowell L. Wood, Jr. asinventors, U.S. application Ser. No. 11/072,007, filed Mar. 4, 2005

4. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation in part of currently co-pendingUnited States patent application entitled SKIN TREATMENT INCLUDINGPATTERNED LIGHT, naming Bran Ferren, Muriel Y. Ishikawa, Edward K. Y.Jung, Nathan P. Myhrvold, Clarence T. Tegreene, and Lowell L. Wood, Jr.as inventors, U.S. application Ser. No. ______, filed contemporaneouslyherewith.

TECHNICAL FIELD

The present application relates, in general, to the field of treatingskin for aesthetic and/or health and/or other purposes. In particularly,this application relates to methods and systems for controlling thedelivery of materials into or onto skin.

BACKGROUND

The introduction of various dyes or other pigmented materials into oronto the skin to in the form of cosmetics or tattoos is well known, asis the application of various biologically active compounds onto or intothe skin surface for various medical-related purposes. In recent years,light-activated photodynamic therapy agents have been developed for thetreatment of various skin problems, including skin cancers.

SUMMARY

According to various embodiments, methods are provided for formingpatterned distributions of materials in the skin of a subject. A desiredpattern may be formed by delivering a photoresponsive material to theskin and exposing the skin to light or other electromagnetic energy tocause a reaction or conversion of the photoresponsive material. In someembodiments, a photoresponsive material may be delivered into or ontothe skin in a pattern. In some embodiments, patterned light may bedelivered to the skin. One or both the photoresponsive material andlight may be patterned in order to form a desired distribution ofmaterial. Materials distributed in or on the skin may have a variety ofproperties for aesthetic, cosmetic, functional, health, or medicalpurposes. Features of various embodiments will be apparent from thefollowing detailed description and associated drawings.

BRIEF DESCRIPTION OF THE FIGURES

Features of the invention are set forth in the appended claims. Theexemplary embodiments may best be understood by making reference to thefollowing description taken in conjunction with the accompanyingdrawings. In the figures, like referenced numerals identify likeelements.

FIG. 1 illustrates focusing of light in a skin region to producemodification of a photoresponsive material;

FIG. 2A illustrates transformation of a photoresponsive substance from afirst form to a second form with exposure to light;

FIG. 2B illustrates cross-linking of a photoresponsive substance onexposure to light;

FIGS. 3A-3C illustrate photopatterning of skin by targeted applicationof light;

FIG. 4A illustrates topical application of a photoresponsive material;

FIG. 4B illustrates diffusion of topically applied photoresponsivematerial into the skin;

FIG. 5A illustrates hypodermal injection of photoresponsive material;

FIG. 5B illustrates diffusion of injected photoresponsive material;

FIG. 6 illustrates injection of photoresponsive material into skin witha microneedle array;

FIG. 7 depicts diffusion of photoresponsive material into skin from acapillary;

FIG. 8 depicts a skin region including a photoresponsive substance;

FIG. 9 depicts targeted application of light to a skin region includinga photoresponsive substance;

FIG. 10 depicts an embodiment of a system for controlled delivery oflight to skin;

FIG. 11 is a flow diagram of a method of forming a pattern in a skinvolume;

FIG. 12 is a flow diagram of a further method of forming a pattern inskin;

FIG. 13 is a flow diagram of a further method of forming a pattern inskin;

FIG. 14 is a block diagram of a system for targeted application of lightto skin;

FIG. 15 is a block diagram of a system for targeted application of lightto skin;

FIG. 16 is a block diagram of an embodiment of a system for controlleddelivery of light to skin;

FIG. 17 is a flow diagram of a method producing a pattern on a surface;

FIGS. 18A-18D depict steps of a method of patterning skin;

FIG. 19A illustrates an embodiment of a mask with a decorative pattern;

FIG. 19B depicts use of the mask depicted in FIG. 19A;

FIG. 19C illustrates a decorative pattern formed on a skin surface withthe use of the mask depicted in FIG. 19A;

FIG. 20 is a flow diagram of a method of forming a patterneddistribution of material in skin;

FIG. 21A illustrates delivery of patterned light to a treated skinsurface;

FIG. 21B illustrates a pattern formed on a skin surface by the patternedlight depicted in FIG. 21A;

FIG. 22 is a flow diagram illustrating variations of methods forphotopatterning of skin;

FIGS. 23A-22C illustrate steps of forming a patterned distribution ofmaterial in skin;

FIG. 24 is a flow diagram illustrating variations of methods forphotopatterning of skin;

FIGS. 25A-25B illustrate patterning of skin by patterned delivery ofphotoresponsive material combined with patterned delivery of light;

FIG. 26 is a block diagram of a system for photopatterning of skin;

FIG. 27 is a flow diagram of a method of photopatterning skin includingreversing the photoreaction;

FIG. 28 is a flow diagram of a method of photopatterning skin includingremoving the modified form of the photoresponsive material;

FIG. 29 is a flow diagram of a method of photopatterning skin includingremoving unmodified photoresponsive material from the skin;

FIG. 30 is a flow diagram of a method of photopatterning an activechemical compound in the skin;

FIG. 31 is a flow diagram of a method of manufacturing a device fordelivering patterned light;

FIG. 32 is a flow diagram of a further method of manufacturing a devicefor delivering patterned light; and

FIG. 33 is a block diagram of a system for delivery of patterned light.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. The detaileddescription and the drawings illustrate specific exemplary embodimentsby which the invention may be practiced. These embodiments are describedin sufficient detail to enable those skilled in the art to practice theinvention. It is understood that other embodiments may be utilized, andother changes may be made, without departing from the spirit or scope ofthe present invention. The following detailed description is thereforenot to be taken in a limiting sense, and the scope of the presentinvention is defined by the appended claims.

Throughout the specification and claims, the following terms take themeanings explicitly associated herein unless the context dictatesotherwise. The meaning of “a”, “an”, and “the” include pluralreferences. The meaning of “in” includes “in” and “on.” A reference tothe singular includes a reference to the plural unless otherwise statedor inconsistent with the disclosure herein.

According to various embodiments as disclosed herein, methods andsystems are provided for forming patterned distributions of materials inor on skin. Patterned distributions of materials in skin may havevarious applications, including but not limited to aesthetic, cosmetic,functions, medical or health purposes. Patterned distributions of dyes,pigments, or other light absorbing, reflecting, or emitting materials,(or any other materials that may produce a visually or opticallydetectable effect) may be used for aesthetic, decorative, or cosmeticpurposes (for example, as tattoos or permanent or semi-permanentcosmetics). Detectable markings, which may be detectable visually oroptically, or by electrical, magnetic, acoustic, or various otherdetection methods, may have functional applications, as well, forexample, marking the location of a surgical site on a patient, or forproviding permanent or semi-permanent identifying markings, e.g., onpets, livestock, etc. Patterned distributions of materials havingpharmaceutical activity may used to selectively treat various structuresin or near the skin surface. Treatment targets may include skin lesions,including cancerous and precancerous skin lesions, moles, warts, andpimples. Treatment may also be applied to disorders of various skinstructures, for example, capillaries, veins, sweat glands, and hairfollicles. In other embodiments, patterned distributions of structuralmaterials (e.g., materials that add strength, form, shape, bulk,resilience, or other desired structural or mechanical properties toskin, connective tissue, cartilage, and so forth) may be used forcosmetic or reconstructive surgery applications. In some cases, a fewexample of which are provided above, it may be desirable to form apattern of material that remains in the skin permanently orsemi-permanently. In other cases, e.g., if the patterned material is abiologically active compound intended to treat a specific medicalproblem, only transient presence of the patterned material may bedesired.

FIG. 1 illustrates modification of a photoresponsive material in skincaused by delivery of light. In FIG. 1, molecules or particles ofphotoresponsive material 10 are distributed throughout skin region 12,and light 14 is targeted to a specific location by lens 16, where itproduces a reaction or other modification of one or more molecules orparticles of photoresponsive material 10 to produce modified form 11.Skin region 12 includes stratum corneum 18 and keratinocyte layer 20,which together form epidermis 22, and dermis 24. Also shown is hairfollicle 26 and hair 28. Photoresponsive material 10 may be distributedin the form of molecules, clusters or aggregations of molecules,particles, gels, solutions, emulsions, suspensions, sprays, fluids,powders, among others. As used herein, the term photoresponsive materialrefers to a material (compound, element, composite material, etc.) thatundergoes or participates in a reaction, interaction, transformation,modification, phase change, change in energetic state, etc.) to producea reaction product, or modified form, indicated by reference number 11in FIG. 1, having one or more different activities or properties thanthe original or ‘unmodified’ photoresponsive material. A “modification”,as used herein may include chemical reactions, changes in energeticstate, phase, conformation, associations, aggregations, formation ofbonds or other interactions (e.g. molecular bonds, hydrogen bonds, vander Waals linkages, etc.), polymerization, cross linking, breaking ofbonds, dissociation of associated molecules, atoms, ions, etc.,oxidation or reduction reactions, formation of ions or free radicals,changes of 3-D molecular structure, being only examples. Photoresponsivematerial may be any material that is responsive or sensitive to light tochange from a first state to a second state, by itself or in cooperationor reaction with other materials present. In some embodiments, aphotoresponsive material may undergo a modification that results in amodification to a secondary material, in which it is the secondarymaterial that produces an effect in the skin. In other embodiments, thephotoreactive material may be employed as a light-specified ‘mask’ whichthen is used to control the exposure of skin not so ‘masked’ tosubsequent processing. Photoresponsive material may include mixtures ofmaterials that react or interact upon exposure to light. FIG. 2A depictsa change in conformation produced by exposure to light, in whichphotoresponsive material 10 is converted from a first state 10 to asecond state 11. FIG. 2B depicts cross linking of multiple molecules 30of photoresponsive material produced by exposure to light, to formcrosslinked network 31. Conversion of a photoreactive material from anunreacted to a reacted form may include conversion from inactive toactive form, from active to inactive form, from colored form tonon-colored form, from a darker form to a lighter one (or vice versa),from a more-scattering form to a less-scattering one (or vice versa),from a first color to a second color, or any combination of these.Conversion of a photoreactive material from an unreacted form to areacted form may include a changes in the scattering or absorptionproperties of the photoreactive material for light of a given waveband.

Various methods of delivering photoresponsive material and light to askin region may be used to produce a patterned distribution of amaterial in the skin region. One or the other or both of thephotoresponsive material and the light may be delivered in a targetedfashion in order to produce a patterned distribution of material in theskin.

In some embodiments, a patterned distribution of a material in or onskin may be produced by delivering a photoresponsive material to atleast a skin region of a subject in a relatively non-targeted fashion,and delivering targeted light to the skin region according to a pattern.The targeted light may have a wavelength content, time-averaged fluxand/or fluence sufficient to cause a transformation of thephotoresponsive material to a modified form. As illustrated in FIGS.3A-3C, the method may include delivering targeted light to the skinregion according to a pattern by delivering targeted light to aplurality of locations in the skin region according to a pattern. Apatterned distribution of the modified form of the photoresponsivematerial may then be formed. This general approach is illustrated inFIG. 3A-3C. In FIG. 3A, a skin region 100 is illustrated.Photoresponsive material has been applied to a portion 102 of skinregion 100. Focused light 106 from light source 108 is delivered tolocation 110 a, which is one of multiple locations 110 a-110 j withinportion 102. FIG. 3B illustrates delivery of light 106 to location 110a, where photoresponsive material is converted to a modified form,indicated by a dark circle. FIG. 3B depicts multiple locations 110 b-110j that have previously been exposed to light to cause modification ofphotoresponsive material. Light source 108 may be positioned withrespect to skin region 108 by a linkage 112. FIG. 3C depicts a patternof modified material at locations 110 a-110 o.

Delivery of photoresponsive material in relatively non-targeted fashionmay be accomplished by various methods, which may depend on variousfactors, including the type of photoresponsive material to be used,desired depth of delivery of the material in the skin, the size of thearea in which a patterned distribution of material is to be produced. Insome embodiments, photoresponsive material may be delivered to the skintopically. As illustrated in FIG. 4A, a carrier material 130 containinga photoresponsive material 132 may be placed on a skin surface 134.Photoresponsive material 132 may diffuse out of carrier material 130 andinto skin 12, as shown in FIG. 4B. Skin 12 includes epidermis 22 anddermis 24. Diffusion of photoresponsive material 132 may be enhanced byelectrophoresis or by the presence of solvent or ‘carrier’ chemicalssuch as DMSO or EDTA in certain embodiments (see, e.g., “PhotodynamicTherapy”, Medscape Dermatology 3(2), 2002, incorporated herein byreference. Photoresponsive material may be delivered to at least a skinregion of a subject topically in various forms, including, for example,an aerosol, cream, emulsion, gel, liquid, vapor, gas, lotion, patch, orpowder or combinations of these.

In some cases, a general distribution of a photoresponsive materialwithin a skin region may be obtained by injecting the photoresponsivematerial 132 into skin 12 with an hypodermic needle 140, as depicted inFIG. 5A. Photoresponsive material 132 may be in a liquid carriersolution 136, or in a suspension, an emulsion, or any other formsuitable for delivery via a hypodermic needle. This approach may besuitable if the diffusion or dispersion of the photoresponsive materialaway from the injection site produces an acceptable (e.g., sufficientlyuniform) distribution of photoresponsive material, as depicted in FIG.5B, within an acceptable amount of time. Alternatively, photoresponsivematerial may be distributed into a skin region 12 with the use of amicroneedle array 150, as depicted in FIG. 6. Photoresponsive material132 may be injected below stratum corneum 18 of skin region 12 with theuse of a microneedle array 150. As described in connection with theembodiment depicted in FIG. 5A, photoresponsive material to be deliveredvia microneedle array 150 may be carried in a carrier fluid 152 that isadapted for use with a microneedle array.

The distribution of photoresponsive material 132 that can be obtainedwithin skin region 12 may depend on the combination of injectionmethodology and photoresponsive material used. For example, smallermolecules may diffuse or disperse more readily from the injection sitethan may larger molecules. In addition, the presence of certainfunctional groups may cause some photoresponsive materials to be takenup by certain tissues or cell types. Accordingly, photoresponsivematerials may be selected or designed for use in combination withcertain delivery mechanism and for preferential delivery to, retentionby, or processing by certain tissues or cells. The design or selectionof photoresponsive materials to have certain diffusion or selectiveuptake-or-retention-or-processing properties may be performed by aperson of skill in the relevant art, for example, as described in Pogueand Hasan, “Targeting in Photodynamic Therapy and Photo-Imaging, Optics& Photonics News, August 2003, pp. 36-43, which is incorporated hereinby reference.

In some embodiments, a photoresponsive material may be delivered to atleast a skin region of a subject by delivering the photoresponsivematerial to the subject systemically. For example, photoresponsivematerial may be delivered to the subject orally in an ingestibleformulation, via an inhalant, via intravenous or other ‘deep’ injectionmodalities or via various other systemic routes. In some cases, aphotoresponsive material may be delivered via injection, butsubsequently carried throughout the body by the blood stream. Asdepicted in FIG. 7, a systemically delivered photoresponsive material132 may be carried in the blood stream (e.g., in capillary 160) anddiffuse out into the skin region of interest, which in this example isskin region 12. Depending on the particular photoresponsive material, itmay distribute uniformly throughout the subject's body, or maydistribute preferentially to certain regions, tissues, or cells of thebody. In this, and other embodiments, the photoresponsive material maybe attached to a carrier molecule compounded in various ways as known tothose of skill in the arts of drug delivery, in order to produce adesired distribution of photoresponsive material within the subject'sbody.

FIG. 8 depicts the arm 200 of a subject, showing a skin region 202 inwhich a photoresponsive material is distributed. In this and otherembodiments, photoresponsive material may be distributed only to theskin region of interest (skin region 202 in the present example), by,for example, topical application or local injection, or it may bedistributed to a larger portion of the subject's body (up to andincluding the entire body), of which the region of interest is a part.In FIG. 9, patterned light 204 is delivered to skin region 202 fromlight source 206 to cause modification of the photoresponsive materialto produce a patterned distribution 208 of the modified material in skinregion 202.

FIG. 10 provides a general illustration of a device 300 that may be usedto produce a patterned distribution of light. Controller 301 controlsthe deliver of light 302 from light source 304 via optical system 306.Device 300 may be positioned by a mechanical linkage 112 supported by abase 140. Light 302 may be delivered at different x,y positions on theskin surface (e.g. x₁, y₁, x₂, y₂, x₃, and y₃ in FIG. 10), as well as atdifferent depths or z positions (e.g. z₁, z₂, and z₃ in FIG. 10) belowthe skin surface 134. Each location may be characterized by an xcoordinate and y coordinate in an effectively planar portion of the skinregion. Similarly, each location may be characterized by z coordinatecorresponding to the depth of the location below a surface of the skinregion. In some applications, the z coordinate may be selected for eachlocation such that a pattern is formed in the epidermis of the skinregion. In other applications, the z coordinate may be selected for eachlocation such that a pattern is formed in the dermis of the skin region,or even below the dermis.

A method as depicted in FIG. 11 may be used for forming a pattern in askin volume. At step 402, a photoresponsive material is delivered to atleast a skin volume of a subject, the skin volume including a regionhaving a depth underlying a skin surface having an area. At step 404,light of a wavelength band, time-averaged flux and/or fluence sufficientto cause modification of the photoresponsive material may be aimed andfocused at a plurality of locations within the volume, with at least aportion of the plurality of locations being at different depths withinthe region.

FIG. 12 depicts steps of a method of forming a patterned distribution ofmaterial in skin, including delivering a photoresponsive material to atleast a skin region of a subject at step 452 and delivering targetedlight to the skin region according to a pattern, the targeted lighthaving a wavelength content, time-averaged flux and/or fluencesufficient to cause a transformation of the photoresponsive material toa modified form, at step 454. FIG. 13 depicts a related method, whichincludes delivering a photoresponsive material to at least a skin regionof a subject at step 472 and delivering targeted light to a plurality oflocations in the skin region according to a pattern, the targeted lighthaving a wavelength content, time-averaged flux and/or fluencesufficient to cause a transformation of the photoresponsive material toa modified form, in step 474.

FIG. 14 is a block diagram of a system 500 for delivering patternedlight. System 500 includes a light source 502 capable of producing light503 of at least one defined wavelength band, and a controllable opticalsystem 504. Controllable optical system 504 is configured to receivecontrol signal 506 generated according to a pattern 508, and responsiveto the control signal 506 to aim and focus light 503 from the lightsource 502 onto one or more selected skin locations of the plurality ofskin locations 510 a-510 p according to pattern 508. Pattern 508 mayrepresent a desired distribution of a material to a plurality oflocations in or on skin region 510. System 500 may also includeelectronic circuitry 512 configured to limit the fluence of light 503produced by the light source 502 to levels that are non-damaging or notsignificantly damaging to skin. Controller 514, which may be, forexample, a microprocessor, may perform computations used to producecontrol signal 506 for controlling controllable optical system 504, andlight source drive signal 515 for driving light production by lightsource 502. Electronic circuitry 512 may function to limit light sourcedrive signal 515 to limit light generation to safe levels. In someembodiments, a system for delivering patterned light to skin may includea light source capable of producing light of at least one definedwavelength band, a controllable optical system, and electronic circuitryconfigured to limit the fluence of light produced by the light source tolevels that are non-damaging or not significantly damaging to skin. Thecontrollable optical system may be configured to receive a controlsignal generated according to a pattern representing a desireddistribution of a material to a plurality of locations in or on a skinregion, and responsive to the control signal to aim and focus light fromthe light source onto one or more selected skin locations of theplurality of skin locations according to the pattern. The system fordelivering patterned light may also include an imaging device adaptedfor imaging a skin region containing at least a portion of the pluralityof skin locations. In some embodiments, the system may include a devicedriver including one or more of hardware, software, or firmware forgenerating the control signal based upon pattern data stored in amachine readable medium. In some embodiments, the controllable opticalsystem may include one or more deflectors configured to aim light fromthe light source, and the position of at least one of the one or morereflectors may be controllable to aim light toward at least one of theplurality of skin locations. In some embodiments, the controllableoptical system may include a positioner adapted to adjust the positionof the light source. Deflectors may include mirror-type reflectors andsurface-acoustic wave (SAW) Bragg-type deflectors, as well aselectrically-steered refractive elements.

Patterned light may be delivered in the form of discrete pulses appliedat multiple locations, as depicted in FIG. 14. Patterned light may alsobe delivered by sweeping a focused beam of light across a skin surfacein a continuous pattern, for example, as depicted in FIG. 15. A beam maybe moved across the skin surface with the use of a scanning mirror orfunctionally-equivalent optical systems of other types, the design anduse of which is well known to those of skill in the art. Patterned lightmay also be delivered in some combination of continuous and discretelight; for example, a beam may be swept across the skin surface to formcontiguous portions of a pattern, but turn on and off as the beam ismoved to non-contiguous portions of the pattern.

FIG. 15 depicts a system 600 including a controllable positioning system602 that may be used to move a beam of light 604 over a skin surface 606and to adjust the positioning of light from the light source on a skinregion. System 600 may include a controllable optical system 608 thatincludes one or more deflectors 610 configured to aim light 604, fromthe light source 612. The position of at least one deflector 610 may becontrollable to aim light 604 toward at least one of the plurality ofskin locations. Controllable optical system 608 may include a positioneradapted to adjust the position of light source 612. Light source 612 maybe capable of producing light 604 of at least one defined wavelengthband. System 600 may also include memory 614 capable of storing apattern 616 in machine-readable form representing a plurality oflocations within a skin region to which light 604 from light source 612is to be directed. In some embodiments, system 600 may include one ormore optical components capable of focusing light 604 from the lightsource 612 at a specific depth within a skin region 12 in response to acontrol signal 618, controller 620 configured to generate control signal618 for driving controllable positioning system 602 to direct light ontoa plurality of skin locations according to pattern 616 stored in memory614. Controller 620 may be configured to generate a control signal fromdriving one or more optical components to adjust the focusing of light604 at different depths and at different skin locations according topattern 616. Deflectors 610 may be controllable deflectors configured toaim light 604 from light source 612, wherein the position of at leastone of the one or more deflectors 610 is controllable to aim lighttoward any of the plurality of skin locations. Controller 620 mayinclude one or more of hardware, software, and firmware. In someembodiments, controller 620 may include a microprocessor. In someembodiments, system 600 may include an imaging device, which may be forexample, a CCD camera.

FIG. 16 is a block diagram of different aspects of a system 700 fordelivering patterned light to a skin region 12. System 700 may includelight source 702 and optical system 704, which directs and focuses light706 from light source 702. Overall system operation may be controlled byprocessor 708, which may be, for example, a microprocessor, powered bypower supply 710. Processor 708 may execute commands from executablecode 712 to generate signals 714 and 716, which are sent to light sourcedriver 718 and optical driver 720, respectively. Light source driver718, which may include hardware, software, firmware, or a combinationthereof, drives operation of light source 702. Optical driver 720, whichalso may include hardware, software, firmware, or a combination thereof,drives operation of optical system 704, via position control module 722and focus control module 724. System 700 may be used to deliver targetedlight to a plurality of locations under software control and/or undermicroprocessor control.

FIG. 17 outlines a method that includes delivering patterned light of arestricted wavelength band to a skin surface coated with aphotosensitive material, wherein the patterned light is capable ofinteracting with the photosensitive material to produce a visiblepattern on the coated surface, as shown at step 752 of the flow diagram.The photosensitive material may be applied to the surface. Light may bedelivered to different locations in sequence, in either discrete orcontinuous fashion. Patterned light as used in certain embodiments maybe produced with the use of a controllable optical system that iscontrollable to focus the light source on at least two of a plurality ofskin locations in sequence. In some embodiments, a controllable opticalsystem may be used that is controllable to focus the light source on atleast two of a plurality of skin locations simultaneously.

In some embodiments, light may be delivered to all parts of a patternsimultaneously. FIG. 18A illustrates a skin region 800 with a treatedregion 802 that contains a photoresponsive material. As describedpreviously, photoresponsive material may be delivered to region 802topically, by injection, or systemically. In step 18B, patterned lightis delivered to area 804 in region 802 through the use of a stencil ormask or other methods as described herein below. Patterned light causesa reaction or transformation of photoresponsive material in area 804, toproduce a pattern 806 of modified material as shown in FIG. 18C. In someembodiments, an additional step may be carried out to remove unmodifiedphotoresponsive material from skin region 800, so that only pattern 806remains in skin region 800, as depicted in FIG. 18D.

Several methods may be used to expose a treated skin region to patternedlight. As shown in FIGS. 19A-19C, a mask (or stencil) 850 may be placedon the skin surface to block exposure of the skin surface to lightexcept in the areas that are to be patterned. FIG. 19A depicts a mask850 having an opaque portion 852 and a light transmitting portion 854.Mask 850 may be placed over a skin region that contains aphotoresponsive material. In the example of FIG. 19B, the skin region isa portion of the arm 858 of a subject. A drape 860 may be used to extendthe covered area of arm 858; various functionally equivalentconfigurations may be devised by a practitioner of skill in the relevantart. Light from light source 862 may cover all of the light transmittingportion 854 of mask 850, as depicted in FIG. 19B. In some alternativeembodiments, light from a light source may cover a portion of a lighttransmitting portion of a mask, and the light source may be moved to oneor more additional regions in order to expose all of the skin regionexposed by the light transmitting portion of the mask. Light source 862may be removed or turned off following exposure to light for a period oftime sufficient to produce a desired modification of the photoresponsivematerial, and mask 830 and drape 860 (if used) removed. As shown in FIG.19C, arm 858 of the subject, bears a patterned distribution 864 ofmodified photoresponsive material that corresponds to the lighttransmitting regions 854 of mask 850.

The method illustrated in FIGS. 19A-19C is summarized in FIG. 20. Atstep 872, a photoresponsive material is delivered to at least a skinregion of a subject. At step 874, a mask is placed over the skin region,the mask including one or more light blocking regions and defining oneor more light transmissive regions to form a pattern. At step 876, theskin region is exposed to light of wavelength band, time-averaged fluxand/or fluence sufficient to produce modification of the photoresponsivematerial within the skin region beneath the one or more lighttransmissive regions defined by the mask. Delivering a photoresponsivematerial may include delivering a photoresponsive material that isconverted from an active form to an inactive form by exposure to light.Alternatively, delivering a photoresponsive material may includedelivering a photoresponsive material that is converted from an inactiveform to an active form by exposure to light. In further embodiments, themethod may also include reversing the photo reaction by exposing theskin region to light of a wavelength band, time-averaged flux and/orfluence sufficient to reverse the reaction. Photo reactions that mayoperate in a first direction at a first wavelength band, time-averagedflux and/or fluence, and which may be reversed at a second wavelengthband, time-averaged flux and/or fluence include, for examplecrosslinking of PEG-cinnamylidene acetate as described in U.S. Pat. No.5,990,193, and reactions of various aromatic diazo dyes, as described inU.S. Pat. No. 5,998,588, both of which are incorporated herein byreference in their entirety.

An alternative method of delivering patterned light is depicted in FIGS.21A and 21B. FIG. 21A depicts a light source 880 that produces patternedlight 882. This may be accomplished by placing a mask over a singlelight source of sufficient size and capable of generating substantiallycollimated light, or by placing multiple smaller light sources, alsocapable of producing relatively parallel light, in a suitablearrangement. Patterned light 882 from light source 880 may then bedelivered to a treated surface 884. In the example of FIG. 21A, treatedsurface 884 need not be masked, because the light is patterned, althoughin some embodiments patterned light may be used in combination with amask or stencil. FIG. 21B illustrates pattern 886 that has been formedby modification of photoresponsive material in or on treated surface 884by exposure to patterned light 882.

As illustrated in FIG. 22, various methods of delivering photoresponsivematerial to a skin region may be combined with various methods ofdelivering targeted light to a skin region to produce a number ofrelated embodiments. Delivering photoresponsive material to at least askin region, at step 902, may be further characterized as deliveringphotoresponsive material topically (step 902 a), deliveringphotoresponsive material by injection in the skin region (902 b) bydelivering photoresponsive material by injection below the stratumcorneum with a microneedle array (902 c), or delivering thephotoresponsive material systemically (902 d). Delivering targeted lightto the skin region according to a pattern, as at step 904, may beperformed by a number of approaches, including delivering targeted lightto a plurality of locations in the skin region according to a pattern(904 a), delivering targeted light to the skin region according to adecorative pattern (step 904 b) or delivering targeted light to the skinregion according to a pattern corresponding to one or more structures inthe skin region (step 904 c). Methods including step 904 c may alsoinclude a step of detecting one or more features in the skin region. Thetarget light may have a wavelength content, time-averaged flux, orfluence sufficient to cause a transformation of the photoresponsivematerial to a modified form.

In some embodiments, a photoresponsive material may be introduced into askin region in a patterned distribution, and light delivered to the skinin a relatively non-targeted fashion in order to cause transformation ofthe photoresponsive material to a modified form. This approach isillustrated in FIGS. 23A-23C. A photoresponsive material may bedelivered topically in a pattern by various methods, including painting,printing (i.g., ink-jet or wire-jet printing), and stenciling, forexample. Photoresponsive material may be delivered into the skin, belowthe skin surface, by injection with one or multiple needles (e.g. tattooneedles, micro-needle array, hypodermic needle) or by a pressure jet.

FIG. 23A illustrates a skin region 950 including a patterneddistribution of photoresponsive material 952. In FIG. 23B, light source954 is used to deliver light to a region 956 which includes patterneddistribution of photoresponsive material 952. Light source 954 deliverslight in a relatively non-targeted fashion; any light distribution thatcovers patterned distribution of photoresponsive material 952 with lightof sufficient intensity or fluence may be used. In some embodiments,light may be delivered in several stages or from several sources, e.g.,by delivering light from two or more sources, or from the same source attwo different times, such that each individual delivery of light coversonly a part of the patterned distribution of photoresponsive material,but that together, the multiple deliveries of light cover the entirepatterned distribution of photoresponsive material. In FIG. 23C,following modification of photoresponsive material due to lightexposure, a patterned distribution of modified material 958 is presentin skin region 950.

In some embodiments, both photoresponsive material and light may bedelivered to the skin in a pattern. Patterned delivery ofphotoresponsive material and of light may be accomplished by any of theexemplary methods described herein above, for example. The patterns maybe substantially similar and overlapping, in which case the distributionpattern of the modified form in or on the skin will be substantially thesame as the distribution patterns of the unmodified form and the light.If the distribution pattern of the photoresponsive material and thedistribution pattern of the light are partially overlapping, a patterneddistribution of the modified form may be obtained that is defined by theshape and distribution of the regions of overlap between thedistribution patterns of photoreactive material and light. This approachis illustrated in FIG. 24 and FIGS. 25A-25C. At step 972 of FIG. 24, aphotoresponsive material is delivered to a skin region of a subject in afirst pattern. In one exemplary variant, 972 a, photoresponsive materialis delivered to the skin region topically. In another exemplary variant972 b, photoresponsive material 972 b is delivered to the skin region byinjection (e.g., via a hypodermic needle, tattoo needle, microneedlearray, pressure jet, etc.) At step 974, targeted light is delivered tothe skin region in a second pattern, the second pattern overlappingpartially with the first pattern. The photoresponsive material in theareas of overlap between the first pattern and the second pattern mayundergo photomodification to form an overlap pattern of modifiedphotoresponsive material within the skin region. The method isillustrated in graphic form in FIGS. 25A-25C. In FIG. 25A, a patterneddistribution of photoresponsive material 1000 is formed in skin region1002. In the present example, patterned distribution of photoresponsivematerial 1000 includes five lines of photoresponsive material 1000 _(a),1000 _(b), 1000 _(c), 1000 _(d), and 1000 _(e). Such a patterneddistribution may be formed by printing, injection, or other methods asdescribed herein or as may be devised by one of skill in the art. InFIG. 25B, a patterned distribution of light 1004 is delivered to skinregion 1002, overlapping patterned distribution of photoresponsivematerial 1000. Patterned distribution of light 1004 in this exampleincludes five lines of light, 1004 ₁, 1004 ₂, 1004 ₃, 1004 ₄, and 1004₅, which may be formed by various methods as described previously.Following exposure to light, the photoresponsive material may react toform the patterned distribution 1006 of modified material in skin region1002, as shown in FIG. 25C. Patterned distribution 1006 includes regions1006 r, where r=1 . . . 5 and c=a . . . e, formed by areas of overlapbetween patterned distribution of photoresponsive material 1000 andpatterned distribution of light 1004.

In some embodiments, it may be desirable to detect an image of a skinregion in which a patterned distribution of a material is to be formed.For example, it may be desirable to detect a feature in a skin regionthat may be a treatment target, prior to delivery of a treatment in atargeted or aligned fashion. Or, it may be desirable to view an image ofthe skin region in order to determine placement of a decorative patternin or on the skin region, e.g., aligned relative to a portion of apreviously-emplaced pattern. FIG. 26 is a block diagram of a system 1050that includes an imaging device 1052. System 1050 may include a lightsource 1054 capable of producing light of at least one definedwavelength band, memory 1056 capable of storing a pattern inmachine-readable form representing a plurality of locations within askin region to which light from the light source is to be directed,controllable positioning system 1060 configured to adjust thepositioning of light from light source 1054 on a skin region, one ormore optical components 1062 capable of focusing light from the lightsource 1054 at a specific depth within a skin region in response to acontrol signal, and controller 1064 configured to generate a controlsignal 1066 for driving controllable positioning system 1060 to directlight onto a plurality of skin locations according to the pattern 1058stored in memory 1056. In some embodiments, controller 1064 may beconfigured to generate control signal 1066 for driving opticalcomponents 1062 to adjust the focusing of light at different depths andat different skin locations according to pattern 1058 stored in memory1056. In some embodiments, controllable positioning system 1060 includesone or more controllable deflectors configured to aim light from lightsource 1054, wherein the position of at least one of the deflectors iscontrollable to aim light toward any of the plurality of skin locations.System 1050 may also include one or more I/O devices 1068 to provide forentry of control inputs by a user and for the presentation ofinformation or data to the user. Various types of I/O devices are knownor may be developed by those of skill in the arts of electronics andsensors for receipt and presentation of information and data in audio,visual, electronic, tactile, or other form, examples of which includescanners, touchscreens, keyboards, mice, trackballs, buttons, dials,microphones, speakers, video displays, etc. Controller 1064 may includeone or more of hardware, software, and firmware. In some embodiments,controller 1064 may include a microprocessor. System 1050 may include animaging device, which may be, for example, a CCD camera.

In various embodiments, examples of which are described herein,photoresponsive materials may be delivered to at least a skin region ofa subject, and some or all of the photoresponsive material may beexposed to light to cause a reaction or conversion of thephotoresponsive material. In some applications it may be desirable toremove one or both of modified and unmodified material from thesubject's body. Unwanted material may be removed by processes normallyoccurring in the body, such as metabolism or excretion of the material,or by sluffing of skin containing the material. In some cases, materialsmay not be removed by naturally occurring processes, or may not beremoved as quickly as is deemed desirable, and further treatment stepsmay be used to remove the materials form the body. In some embodiments,unmodified material may be removed, while modified material may be leftin the skin region. In some embodiments, modified material may beremoved from the skin region after a use period. Treatment to removedeither modified or unmodified photoresponsive material, or both, mayinclude phototreatment (e.g., photobleaching), chemical treatment (e.g.,chemical bleaching), chemo-mechanical treatment, or treatment byexposure to heat, vibration, electromagnetic fields, among others.

FIG. 27 depicts an exemplary sequence of method steps. At step 1102, aphotoresponsive material is delivered to at least a skin region of asubject. At step 1104, a mask is placed over the skin region, the maskincluding one or more light blocking regions and defining one or morelight transmissive regions to form a pattern. At step 1106, the skinregion may be exposed to light of wavelength band, time-averaged fluxand/or fluence sufficient to produce modification of the photoresponsivematerial within the skin region beneath the one or more lighttransmissive regions beneath the mask. Method steps 1102 through 1106correspond to the method illustrated in FIGS. 19A-19C, for example. Atstep 1108, the modification is reversed by exposing the skin region tolight of wavelength, time-averaged flux and/or fluence sufficient toreverse the modification.

Various of the methods disclosed herein (for example, the method asoutlined in FIG. 12), may include removal of the modified form of thephotoresponsive material from the skin region over time. In someembodiments, the modified form may be removed from the skin region bymetabolism. The modified form may be removed from the skin regionthrough sluffing of dead skin cells and/or the continual shedding ofepidermal outer layers, for example. In some embodiments, the modifiedform may be removed from the skin region after a treatment period. Themethod may include removing the modified form by a photo treatment, by achemical treatment, or by a chemo-mechanical treatment.

FIG. 28 depicts steps of a method that includes removing the modifiedform of the photoresponsive material from the skin region after atreatment period. At step 1152, a photoresponsive material is deliveredto at least a skin region of a subject. At step 1154, targeted light isdelivered to the skin region according to a pattern, the targeted lighthaving a wavelength content, time-averaged flux and/or fluencesufficient to cause a transformation of the photoresponsive material toa modified form. At step 1156, the modified form is removed from theskin region after a treatment period. The modified form may be removedby photo treatment (step 1156 a) or by chemical treatment (1156 b), forexample. The treatment period may be quite brief, producing only atransient presence of the modified material in the system, or may be ofextended duration, of hours, days, weeks, months, or even years.

Examples of photoresponsive materials that may be used in variousembodiments include, but are not limited to photodynamic therapy agents,photochromic dyes and pigments, photo-crosslinkable materials,photopolymerizable materials, and photodimerizable materials, luminides,light reactive polymers that change in conformation, volume, bindingactivity, drug activity, hydrogels of various types. Various exemplaryphotoresponsive materials are described in U.S. Pat. Nos. 6,602,975;5,998,588; 6,555,663; 5,990,193; and 6,818,018, which are incorporatedherein by reference in their entirety. Photoresponsive materials may becosmetic materials having selected color or other appearance properties.Reaction undergone by photoresponsive materials may be a reversibletransformation or an irreversible transformation. In some embodiments,the transformation may convert the photoresponsive material from anactive to an inactive form. In other embodiments, the transformation mayconvert the photoresponsive material from an inactive to an active form.The transformation may include, for example, conversion of aphotoresponsive material from a substantially colorless form to acolored form, or from a colored form to a substantially colorless form.Examples of photochromic dyes are listed in U.S. Pat. No. 6,602,975,which is incorporated herein by reference. In some embodiments, thetransformation may include conversion of the photoresponsive materialfrom a first color to a second color, or may modify the extent to whichit scatters light of a given waveband. The modified form may be visibleunder natural light in some embodiments. In some embodiments, themodified form may be visible under ultraviolet light. In someembodiments, the modified form may be fluorescent. The modified form maybe a pigment, dye, pharmaceutical compound, or cosmetic material.

FIG. 29 depicts steps of a method that includes removing unmodifiedphotoresponsive material from a skin region of a subject. At step 1202,a photoresponsive material is delivered to at least a skin region of asubject. At step 1204, targeted light is delivered to the skin regionaccording to a pattern, the targeted light having a wavelength content,time-averaged flux and/or fluence sufficient to cause a transformationof the photoresponsive material to a modified form. At step 1206, theunmodified photoresponsive material is removed from the skin region. Theunmodified photoresponsive material may be removed by phototreatment, asshown in step 1206 a, or by chemical treatment, as shown in step 1206 b.

FIG. 30 illustrates a method of providing controlled delivery of anactive compound to a skin region, which includes delivering an inactivechemical compound non-specifically to at least a skin region of asubject at step 1252 and exposing the skin region to targeted lightdelivered to multiple selected locations within the skin region to forma pattern at step 1254, the targeted light having a wavelength band,time-averaged flux and/or fluence sufficient to cause modification ofthe inactive chemical compound to form an active compound within theskin region at the selected locations according to the pattern. Asillustrated by steps 1252 a and 1252 b, respectively, delivering aninactive chemical compound may include delivering an inactive form of aphotodynamic therapy agent or a photochromic dye or pigment. It iswithin the present inventive scope to deliver two-or-more materials inthis manner, and to induce reactions between the two-or-more of them orbetween the two-or-more of them and ambient materials by the action ofthe incident light.

Systems for the delivery of light to skin, as described herein, mayinclude various types of light sources. In general, light sources mustdeliver light having wavelength content, fluxes and fluences sufficientto produce a particular effect in the photoresponsive material that isbeing exposed to the light. For example, in some embodiments, the lightmay have a wavelength content, time-averaged flux and/or fluencesufficient to cause a photo cross-linking reaction of thephotoresponsive material. In other embodiments, the light may havewavelength content, time-averaged flux and/or fluence sufficient tocause a photochromic reaction of the photoresponsive material. In stillother embodiments, the light may have a wavelength content,time-averaged flux and/or fluence sufficient to cause aphotodimerization reaction of the photoresponsive material. Lightsources suitable for use in various embodiments as described hereininclude lasers, laser diodes, as well as various non-coherent lightsources. Light sources may include light emitting diodes. In someembodiments, light sources may emit light in an ultraviolet wavelengthband. In some embodiments, light sources may emit light in a visiblewavelength band, or in an infrared one. Broad-band light sources may beused in some embodiments.

FIG. 31 depicts a method of manufacturing a targeted light deliverysystem. Step 1302 includes providing a housing configured to bepositioned relative to a skin region of a subject. At step 1304, a lightsource is mounted in fixed relationship with respect to the housing, thelight source capable of delivering light of a wavelength band,time-averaged flux and/or fluence sufficient to activate aphotoresponsive material in a skin region when the housing is positionedrelative to the skin region. At step 1306, a controllable optical systemis mounted with respect to the housing and the light source such thatlight from the light source may be focused on a skin region by thecontrollable optical system when the housing is positioned relative tothe skin region. At step 1308, driver interface circuitry is connectedto the light source and the controllable optical system, the driverinterface circuitry adapted to receive one or more control signals andresponsive to the control signals to drive the controllable opticalsystem and the light source to focus light on one or more targets in theskin region according to a pattern and/or in an aligned manner.

FIG. 32 depicts a method of manufacturing a device for deliveringpatterned light. A housing is provided that is configured to bepositioned adjacent to a skin region of a subject. At step 1354, a lightsource is mounted in fixed relationship with respect to the housing, thelight source capable of delivering light of a wavelength band,time-averaged flux and/or fluence sufficient to activate aphotoresponsive material in a skin region when the housing is positionedadjacent to the skin region. A controllable optical system is mountedwith respect to the housing and the light source such that light fromthe light source may be focused on a skin region by the controllableoptical system when the housing is positioned relative to the skinregion at step 1356. At step 1358, driver interface circuitry isconnected to the light source and the controllable optical system, thedriver interface circuitry adapted to receive one or more controlsignals from a microprocessor-based controller and responsive to thecontrol signals to drive the controllable optical system and the lightsource to focus light on one or more locations in the skin regionaccording to a pattern. At step 1360, software code is provided that isexecutable by the microprocessor based controller to generate the one ormore control signals. In some embodiments, the driver interfacecircuitry may be adapted to receive the one or more control signals froma microprocessor-based controller. In some embodiments, the method mayinclude providing software code executable by the microprocessor-basedcontroller to generate the one or more control signals.

FIG. 33 depicts features of a device as described in connection withFIG. 32; included are housing 1400, light source 1402, controllableoptical system 1404, and driver interface circuitry 1406. Driverinterface circuitry receives at least one control signal 1408 on input1410, and generates control signals 1412 and 1414 for driving lightsource 1402 and controllable optical system 1404, respectively. Portion1416 of housing 1400 may be configured to be positioned adjacent a skinregion 1418, so that light 1420 may be directed to skin region 1418 bycontrollable optical system 1404.

The methods, apparatuses, and approaches described herein may bemodified and combined in a variety of ways analogous to those ofphotolithography of silicon wafers. For example, masks or stencils maybe used to form positive or negative patterns. Additive and subtractiveprocessing may be performed by appropriate combinations of steps. Forexample, multiple steps, each involving the use of a different stenciland a different depth of focus of light in the skin, may be used to forma patterned distribution of material that varies as a function of depthwithin the skin. As another example, a multi-step process may be used inwhich a material modified at a first step, for example by treatment at afirst wavelength, may in turn influence (e.g. by causing, preventing,promoting, or inhibiting) a further reaction or modification of the sameor a different material produced at a second step by treatment with asecond wavelength. It will appreciated that a wide variety ofcombination of treatment steps may be devised to control formation ofpatterned distributions of material in skin. As with photolithographymethods, as multiple steps involving patterned delivery of materials orlight to the skin are used, it may be necessary to maintain alignment orregistration of patterns delivered at each step, e.g. by controllingmask positioning or targeting of light or delivery of photoresponsivematerial. Methods of maintaining positioning, targeting, or alignmentare known to those of skill in the art, and variations are considered tofall within the scope of the present invention.

With regard to the hardware and/or software used in the control of skintreatment systems according to the present embodiments, and particularlyto the sensing, analysis, and control aspects of such systems, thosehaving skill in the art will recognize that the state of the art hasprogressed to the point where there is little distinction left betweenhardware and software implementations of aspects of systems; the use ofhardware or software is generally (but not always, in that in certaincontexts the choice between hardware and software can becomesignificant) a design choice representing cost vs. efficiency orimplementation convenience tradeoffs. Those having skill in the art willappreciate that there are various vehicles by which processes and/orsystems described herein can be effected (e.g., hardware, software,and/or firmware), and that the preferred vehicle will vary with thecontext in which the processes are deployed. For example, if animplementer determines that speed and accuracy are paramount, theimplementer may opt for a hardware and/or firmware vehicle;alternatively, if flexibility is paramount, the implementer may opt fora solely software implementation; or, yet again alternatively, theimplementer may opt for some combination of hardware, software, and/orfirmware. Hence, there are several possible vehicles by which theprocesses described herein may be effected, none of which is inherentlysuperior to the other in that any vehicle to be utilized is a choicedependent upon the context in which the vehicle will be deployed and thespecific concerns (e.g., speed, flexibility, or predictability) of theimplementer, any of which may vary. For example, those skilled in theart will recognize that optical aspects of implementations will requireoptically-oriented hardware, software, and or firmware.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, flowcharts,and/or examples. Insofar as such block diagrams, flowcharts, and/orexamples contain one or more functions and/or operations, it will beimplicitly understood by those with skill in the art that each functionand/or operation within such block diagrams, flowcharts, or examples canbe implemented, individually and/or collectively, by a wide range ofhardware, software, firmware, or virtually any combination thereof. Inone embodiment, several portions of the subject matter subject matterdescribed herein may be implemented via Application Specific IntegratedCircuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signalprocessors (DSPs), or other integrated formats. However, those skilledin the art will recognize that some aspects of the embodiments disclosedherein, in whole or in part, can be equivalently implemented in standardintegrated circuits, as one or more computer programs running on one ormore computers (e.g., as one or more programs running on one or morecomputer systems), as one or more programs running on one or moreprocessors (e.g., as one or more programs running on one or moremicroprocessors), as firmware, or as virtually any combination thereof,and that designing the circuitry and/or writing the code for thesoftware and/or firmware would be well within the capabilities of one ofskill in the art in light of this disclosure. In addition, those skilledin the art will appreciate that certain mechanisms of the subject matterdescribed herein are capable of being distributed as a program productin a variety of forms, and that an illustrative embodiment of thesubject matter described herein applies equally regardless of theparticular type of signal bearing media used to actually carry out thedistribution. Examples of a signal bearing media include, but are notlimited to, the following: recordable type media such as floppy disks,hard disk drives, CD ROMs, digital tape, and computer memory; andtransmission type media such as digital and analog communication linksusing TDM or IP based communication links (e.g., links carryingpacketized data).

In a general sense, those skilled in the art will recognize that thevarious aspects described herein which can be implemented, individuallyand/or collectively, by a wide range of hardware, software, firmware, orany combination thereof can be viewed as being composed of various typesof “electrical circuitry.” Consequently, as used herein “electricalcircuitry” includes, but is not limited to, electrical circuitry havingat least one discrete electrical circuit, electrical circuitry having atleast one integrated circuit, electrical circuitry having at least oneapplication specific integrated circuit, electrical circuitry forming ageneral purpose computing device configured by a computer program (e.g.,a general purpose computer configured by a computer program which atleast partially carries out processes and/or devices described herein,or a microprocessor configured by a computer program which at leastpartially carries out processes and/or devices described herein),electrical circuitry forming a memory device (e.g., forms of randomaccess memory), and/or electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, or optical-electricalequipment).

Those skilled in the art will recognize that it is common within the artto describe devices for detection or sensing, signal processing, anddevice control in the fashion set forth herein, and thereafter usestandard engineering practices to integrate such described devicesand/or processes into skin treatment systems as exemplified herein. Thatis, at least a portion of the devices and/or processes described hereincan be integrated into a skin treatment system via a reasonable amountof experimentation.

Those having skill in the art will recognize that systems as describedherein may include one or more of a memory such as volatile andnon-volatile memory, processors such as microprocessors and digitalsignal processors, computational-supporting or -associated entities suchas operating systems, user interfaces, drivers, sensors, actuators,applications programs, one or more interaction devices, such as dataports, control systems including feedback loops and control implementingactuators (e.g., devices for sensing position and/or velocity and/oracceleration or time-rate-of-change thereof; control motors for movingand/or adjusting components). A skin treatment system may be implementedutilizing any suitable available components, combined with standardengineering practices.

The foregoing-described aspects depict different components containedwithin, or connected with, different other components. It is to beunderstood that such depicted architectures are merely exemplary, andthat in fact many other architectures can be implemented which achievethe same functionality. In a conceptual sense, any arrangement ofcomponents to achieve the same functionality is effectively “associated”such that the desired functionality is achieved. Hence, any twocomponents herein combined to achieve a particular functionality can beseen as “associated with” each other such that the desired functionalityis achieved, irrespective of architectures or intermediate components.Likewise, any two components so associated can also be viewed as being“operably connected”, or “operably coupled”, to each other to achievethe desired functionality.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be obvious to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from this subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true spirit and scope of this subject matter describedherein. Furthermore, it is to be understood that the invention isdefined by the appended claims. It will be understood by those withinthe art that, in general, terms used herein, and especially in theappended claims (e.g., bodies of the appended claims) are generallyintended as “open” terms (e.g., the term “including” should beinterpreted as “including but not limited to,” the term “having” shouldbe interpreted as “having at least,” the term “includes” should beinterpreted as “includes but is not limited to,” etc.). It will befurther understood by those within the art that if a specific number ofan introduced claim recitation is intended, such an intent will beexplicitly recited in the claim, and in the absence of such recitationno such intent is present. For example, as an aid to understanding, thefollowing appended claims may contain usage of the introductory phrases“at least one” and “one or more” to introduce claim recitations.However, the use of such phrases should NOT be construed to imply thatthe introduction of a claim recitation by the indefinite articles “a” or“an” limits any particular claim containing such introduced claimrecitation to inventions containing only one such recitation, even whenthe same claim includes the introductory phrases “one or more” or “atleast one” and indefinite articles such as “a” or “an” (e.g., “a” and/or“an” should typically be interpreted to mean “at least one” and/or “oneor more”); the same holds true for the use of definite articles used tointroduce claim recitations. In addition, even if a specific number ofan introduced claim recitation is explicitly recited, those skilled inthe art will recognize that such recitation should typically beinterpreted to mean at least the recited number (e.g., the barerecitation of “two recitations,” without other modifiers, typicallymeans at least two recitations, or two or more recitations).Furthermore, in those instances where a convention analogous to “atleast one of A, B, and C, etc.” is used, in general such a constructionis intended in the sense of one having skill in the art would understandthe convention (e.g., “a system having at least one of A, B, and C”would include but not be limited to systems that have A alone, B alone,C alone, A and B together, A and C together, B and C together, and/or A,B, and C together). In those instances where a convention analogous to“at least one of A, B, or C, etc.” is used, in general such aconstruction is intended in the sense of one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, or C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together).

Although the methods, devices, systems and approaches herein have beendescribed with reference to certain preferred embodiments, otherembodiments are possible. As illustrated by the foregoing examples,various choices of light delivery system configuration and method ofdelivery of photoresponsive material may be within the scope of theinvention. As has been discussed, the choice of system configuration maydepend on the intended application of the system, the environment inwhich the system is used, cost, personal preference or other factors.System design, manufacture, and control processes may be modified totake into account choices of photoresponsive material and intendedapplication, and such modifications, as known to those of skill in thearts of display design and construction, may fall within the scope ofthe invention. Therefore, the full spirit or scope of the invention isdefined by the appended claims and is not to be limited to the specificembodiments described herein.

1.-54. (canceled)
 55. A method of producing a patterned distribution ofa material within a skin region, comprising: delivering aphotoresponsive material to a skin region of a subject in a firstpattern; and delivering targeted light to the skin region in a secondpattern, said second pattern overlapping partially with said firstpattern, wherein photoresponsive material in the areas of overlapbetween said first pattern and said second pattern undergoesphotomodification to form an overlap pattern of modified photoresponsivematerial within said skin region.
 56. The method of claim 55, whereindelivering the photoresponsive material to the skin region includestopically delivering the photoresponsive material to the skin region.57. The method of claim 55, wherein delivering the photoresponsivematerial to the skin region includes injecting the photoresponsivematerial into the skin region.
 58. The method of claim 55, includingdelivering targeted light to said skin region in said second pattern bydelivering targeted light to a plurality of locations in said skinregion according to said second pattern.
 59. The method of claim 58,including delivering targeted light to said plurality of locations bydelivering targeted light to said plurality of locations under softwarecontrol.
 60. The method of claim 58, including delivering targeted lightto said plurality of locations by delivering targeted light to saidplurality of locations under microprocessor control.
 61. The method ofclaim 55, wherein delivering targeted light to said skin region in saidsecond pattern includes delivering targeted light to said skin regionaccording to a decorative pattern.
 62. The method of claim 55, whereindelivering targeted light to said skin region in said second patternincludes delivering targeted light to said skin region according to apattern corresponding to one or more structures in said skin region. 63.The method of claim 56, including topically delivering saidphotoresponsive material to said skin region in the form of an aerosol,cream, emulsion, gel, liquid, fluid, gas, vapor, lotion, patch, powder,or combination thereof.
 64. The method of claim 57, including deliveringsaid photoresponsive material to said skin region by injecting saidphotoresponsive material below the stratum corneum of said skin regionwith the use of a microneedle array.
 65. The method of claim 55, whereinsaid modified photoresponsive material is visible under natural light.66. The method of claim 55, wherein said modified photoresponsivematerial is visible under ultraviolet light.
 67. The method of claim 55,wherein said modified photoresponsive material is fluorescent.
 68. Themethod of claim 55, wherein said modified photoresponsive material is apigment, dye, pharmaceutical compound, or cosmetic material.
 69. Themethod of claim 55, wherein delivering targeted light to said skinregion includes delivering targeted light having wavelength content,time-averaged flux and/or fluence sufficient to cause a photocross-linking reaction of said photoresponsive material.
 70. The methodof claim 55, wherein delivering targeted light to said skin regionincludes delivering targeted light having wavelength content,time-averaged flux and/or fluence sufficient to cause a photochromicreaction of said photoresponsive material.
 71. The method of claim 55,wherein delivering targeted light to said skin region includesdelivering targeted light having wavelength content, time-averaged fluxand/or fluence sufficient to cause a photodimerization reaction or otherphotopolymerization reaction of said photoresponsive material.
 72. Themethod of claim 55, wherein delivering said photoresponsive material tosaid skin region of a subject includes delivering a photochromicmaterial.
 73. The method of claim 55, wherein delivering saidphotoresponsive material to said skin region of a subject includesdelivering a photodynamic therapy agent.